@article{d99a0ae341c3409d862e826192d2b87d,
title = "Identification of spin, valley and moir{\'e} quasi-angular momentum of interlayer excitons",
abstract = "Moir{\'e} superlattices provide a powerful way to engineer the properties of electrons and excitons in two-dimensional van der Waals heterostructures1–8. The moir{\'e} effect can be especially strong for interlayer excitons, where electrons and holes reside in different layers and can be addressed separately. In particular, it was recently proposed that the moir{\'e} superlattice potential not only localizes interlayer exciton states at different superlattice positions, but also hosts an emerging moir{\'e} quasi-angular momentum (QAM) that periodically switches the optical selection rules for interlayer excitons at different moir{\'e} sites9,10. Here, we report the observation of multiple interlayer exciton states coexisting in a WSe2/WS2 moir{\'e} superlattice and unambiguously determine their spin, valley and moir{\'e} QAM through novel resonant optical pump–probe spectroscopy and photoluminescence excitation spectroscopy. We demonstrate that interlayer excitons localized at different moir{\'e} sites can exhibit opposite optical selection rules due to the spatially varying moir{\'e} QAM. Our observation reveals new opportunities to engineer interlayer exciton states and valley physics with moir{\'e} superlattices for optoelectronic and valleytronic applications.",
author = "Chenhao Jin and Regan, {Emma C.} and Danqing Wang and {Iqbal Bakti Utama}, M. and Yang, {Chan Shan} and Jeffrey Cain and Ying Qin and Yuxia Shen and Zhiren Zheng and Kenji Watanabe and Takashi Taniguchi and Sefaattin Tongay and Alex Zettl and Feng Wang",
note = "Funding Information: This work was supported primarily by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under contract no. DE-AC02-05-CH11231 (van der Waals heterostructures program, KCWF16). PLE spectroscopy of the heterostructure is supported by the US Army Research Office under MURI award W911NF-17-1-0312. The growth of hBN crystals was supported by the Elemental Strategy Initiative conducted by the MEXT, Japan and JSPS KAKENHI grant no. JP15K21722. S.T. acknowledges support from an NSF DMR 1552220 NSF CAREER award for the growth of WS2 and WSe2 crystals. E.C.R. acknowledges support from the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program. C.-S.Y. acknowledges support from grant no. 107-2112-M-003-014-MY3 from the Ministry of Science and Technology. Publisher Copyright: {\textcopyright} 2019, The Author(s), under exclusive licence to Springer Nature Limited.",
year = "2019",
month = nov,
day = "1",
doi = "10.1038/s41567-019-0631-4",
language = "English",
volume = "15",
pages = "1140--1144",
journal = "Nature Physics",
issn = "1745-2473",
publisher = "Nature Publishing Group",
number = "11",
}